Harness Self-Evolution Plugin
A MoonBit-native plugin that scans, monitors, proposes, and rolls back evolutions for the DeepSeek Harness (DSH) plugin ecosystem. Version 3.0.0. MIT.
This plugin targets DeepSeek Harness. Deployment hinges on how DSH launches the binary, where data is read and written, and which files (patches, manifests, panels) sit alongside the binary.
Where your data lives
DSH resolves its home via $DSH_HOME (~/.dsh by default; a managed launcher may point it
elsewhere). The plugin mirrors that: user-scope sub-agent definitions land under
<DSH home>/skills/. Full install, verification, and rollback:
docs/deploy/deepseek-harness.md.
Since v3.0.0 the plugin is DSH-only: the earlier claim of MiniMax Code compatibility was a
over-declaration (DSH's own source has no such host concept) and has been removed.
If you are writing or debugging a DSH plugin rather than deploying this one, read docs/dsh-plugin-integration.md: the host-half / client-half contract, the Lazy-CJS client bundle rule (one stray top-level export breaks every plugin in the combo), DSH_HOME routing, and the diagnosis order for "Failed to load plugins".
What it does
- Scan installed plugins across the configured scan roots for the active host
- Monitor call latency, success rate, token usage, retry count, and user feedback
- Identify strong signals (user override, three consecutive failures, > 20% latency regression) and medium signals (repeated parameter misuses, loop detection, repeated preferences)
- Propose benchmark-driven evolutions bound to Matt Pocock engineering principles
- Approve is always a human step.
auto_approve is false by default and stays false — the only gate against "code changes itself into a wall"
- Execute with state machine
pending → approved → executing → completed, with deterministic rollback from a verified snapshot on validator failure
- Sub-agent factory persists Markdown + YAML frontmatter definitions; scope
plugin lives under the plugin's data root, scope user lives under <DSH home>/skills/ (see the deploy guide)
Architecture in one paragraph
The compiled binary (bin/harness-evolution.exe) is a stdio MCP server exposing fourteen tools. The user-scope path resolves through src/store/paths.mbt::dsh_agents_dir (<DSH home>/skills, $DSH_HOME-aware), and the scan roots through src/scanner/scanner.mbt::default_scan_roots; HARNESS_EVOLUTION_USER_DIR overrides the user directory explicitly. Since v3.0.0 the multi-host abstraction is gone — DSH is the only target.
See docs/code-architecture.md for the path-resolution detail.
Build
.\build.ps1 -Task all # check + test + build; one command rebuilds the binary
Build prerequisites: MoonBit >=0.1.20260904, MSVC or Clang on Linux/macOS. The current binary in bin/harness-evolution.exe is Windows-native; rebuilding on the target platform produces a native binary for that platform.
Data and configuration
The plugin stores proposals, metrics, signals, cache, and execution log under $HARNESS_EVOLUTION_HOME (default ~/.harness-evolution/v2/). Override with the env var to keep dev/test data separate.
Configuration is read in this order, first file that exists wins:
$HARNESS_EVOLUTION_CONFIG (explicit override)<cwd>/.dsh-plugin/plugin.json (self-manifest).dsh-plugin/plugin.json (relative to plugin root)
If none exist the plugin starts with built-in defaults — missing config is not a startup failure.
Breaking change (unreleased v2.7.0): the legacy <cwd>/.zcode-plugin/plugin.json fallback is no longer read. A deployed instance that still carries that file must rename it to .dsh-plugin/plugin.json — the contents need no change.
Installing into the right tree (DSH_HOME)
Installing is per DSH tree: dsh plugin add writes into $DSH_HOME/profiles/<name>, and $DSH_HOME
decides which tree boots (~/.dsh by default — a managed launcher may point it somewhere else). Trees
share nothing: bundles, node_modules, sessions, and skills are all per-tree, so an install verified in
one tree stays invisible to a host booting another. dsh.profile.bundles is read at boot, so the host must
be restarted before the fourteen mcp__harness-evolution__* tools appear in a session.
$env:DSH_HOME # which tree is dsh touching?
dsh --profile web --dump-config | Select-String 'mcp-harness-evolution' # already mounted in this tree?
Full install, verification, and rollback: docs/deploy/deepseek-harness.md;
the live-install practice (multi-home reality, .dsh-module-fallback pitfalls):
docs/dsh-compatibility.md.
License
MIT. See LICENSE.
